/** @file
  PCI Root Bridge Io Protocol implementation

  Copyright (c) 2008 - 2012, Intel Corporation. All rights reserved.<BR>

  This program and the accompanying materials are licensed and made available
  under the terms and conditions of the BSD License which accompanies this
  distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/

#include "PciHostBridge.h"
#include "IoFifo.h"

typedef struct {
  EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR     SpaceDesp[TypeMax];
  EFI_ACPI_END_TAG_DESCRIPTOR           EndDesp;
} RESOURCE_CONFIGURATION;

RESOURCE_CONFIGURATION Configuration = {
  {{0x8A, 0x2B, 1, 0, 0, 0, 0, 0, 0, 0},
  {0x8A, 0x2B, 0, 0, 0, 32, 0, 0, 0, 0},
  {0x8A, 0x2B, 0, 0, 6, 32, 0, 0, 0, 0},
  {0x8A, 0x2B, 0, 0, 0, 64, 0, 0, 0, 0},
  {0x8A, 0x2B, 0, 0, 6, 64, 0, 0, 0, 0},
  {0x8A, 0x2B, 2, 0, 0, 0, 0, 0, 0, 0}},
  {0x79, 0}
};

//
// Protocol Member Function Prototypes
//

/**
  Polls an address in memory mapped I/O space until an exit condition is met,
  or a timeout occurs.

  This function provides a standard way to poll a PCI memory location. A PCI
  memory read operation is performed at the PCI memory address specified by
  Address for the width specified by Width. The result of this PCI memory read
  operation is stored in Result. This PCI memory read operation is repeated
  until either a timeout of Delay 100 ns units has expired, or (Result & Mask)
  is equal to Value.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operations.

  @param[in]   Address   The base address of the memory operations. The caller
                         is responsible for aligning Address if required.

  @param[in]   Mask      Mask used for the polling criteria. Bytes above Width
                         in Mask are ignored. The bits in the bytes below Width
                         which are zero in Mask are ignored when polling the
                         memory address.

  @param[in]   Value     The comparison value used for the polling exit
                         criteria.

  @param[in]   Delay     The number of 100 ns units to poll. Note that timer
                         available may be of poorer granularity.

  @param[out]  Result    Pointer to the last value read from the memory
                         location.

  @retval EFI_SUCCESS            The last data returned from the access matched
                                 the poll exit criteria.

  @retval EFI_INVALID_PARAMETER  Width is invalid.

  @retval EFI_INVALID_PARAMETER  Result is NULL.

  @retval EFI_TIMEOUT            Delay expired before a match occurred.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPollMem (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN  UINT64                                 Address,
  IN  UINT64                                 Mask,
  IN  UINT64                                 Value,
  IN  UINT64                                 Delay,
  OUT UINT64                                 *Result
  );

/**
  Reads from the I/O space of a PCI Root Bridge. Returns when either the
  polling exit criteria is satisfied or after a defined duration.

  This function provides a standard way to poll a PCI I/O location. A PCI I/O
  read operation is performed at the PCI I/O address specified by Address for
  the width specified by Width. The result of this PCI I/O read operation is
  stored in Result. This PCI I/O read operation is repeated until either a
  timeout of Delay 100 ns units has expired, or (Result & Mask) is equal to
  Value.

  @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in] Width     Signifies the width of the I/O operations.

  @param[in] Address   The base address of the I/O operations. The caller is
                       responsible for aligning Address if required.

  @param[in] Mask      Mask used for the polling criteria. Bytes above Width in
                       Mask are ignored. The bits in the bytes below Width
                       which are zero in Mask are ignored when polling the I/O
                       address.

  @param[in] Value     The comparison value used for the polling exit criteria.


  @param[in] Delay     The number of 100 ns units to poll. Note that timer
                       available may be of poorer granularity.

  @param[out] Result   Pointer to the last value read from the memory location.

  @retval EFI_SUCCESS            The last data returned from the access matched
                                 the poll exit criteria.

  @retval EFI_INVALID_PARAMETER  Width is invalid.

  @retval EFI_INVALID_PARAMETER  Result is NULL.

  @retval EFI_TIMEOUT            Delay expired before a match occurred.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPollIo (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN  UINT64                                 Address,
  IN  UINT64                                 Mask,
  IN  UINT64                                 Value,
  IN  UINT64                                 Delay,
  OUT UINT64                                 *Result
  );

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge memory space.

  The Mem.Read(), and Mem.Write() functions enable a driver to access PCI
  controller registers in the PCI root bridge memory space.
  The memory operations are carried out exactly as requested. The caller is
  responsible for satisfying any alignment and memory width restrictions that a
  PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operation.

  @param[in]   Address   The base address of the memory operation. The caller
                         is responsible for aligning the Address if required.

  @param[in]   Count     The number of memory operations to perform. Bytes
                         moved is Width size * Count, starting at Address.

  @param[out]  Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.

  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoMemRead (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  OUT    VOID                                   *Buffer
  );

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge memory space.

  The Mem.Read(), and Mem.Write() functions enable a driver to access PCI
  controller registers in the PCI root bridge memory space.
  The memory operations are carried out exactly as requested. The caller is
  responsible for satisfying any alignment and memory width restrictions that a
  PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operation.

  @param[in]   Address   The base address of the memory operation. The caller
                         is responsible for aligning the Address if required.

  @param[in]   Count     The number of memory operations to perform. Bytes
                         moved is Width size * Count, starting at Address.

  @param[in]   Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.

  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoMemWrite (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  IN     VOID                                   *Buffer
  );

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge I/O space.

  @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width       Signifies the width of the memory operations.

  @param[in]   UserAddress The base address of the I/O operation. The caller is
                           responsible for aligning the Address if required.

  @param[in]   Count       The number of I/O operations to perform. Bytes moved
                           is Width size * Count, starting at Address.

  @param[out]  UserBuffer  For read operations, the destination buffer to store
                           the results. For write operations, the source buffer
                           to write data from.


  @retval EFI_SUCCESS              The data was read from or written to the PCI
                                   root bridge.

  @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER    Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a
                                   lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoIoRead (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 UserAddress,
  IN     UINTN                                  Count,
  OUT    VOID                                   *UserBuffer
  );

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge I/O space.

  @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width       Signifies the width of the memory operations.

  @param[in]   UserAddress The base address of the I/O operation. The caller is
                           responsible for aligning the Address if required.

  @param[in]   Count       The number of I/O operations to perform. Bytes moved
                           is Width size * Count, starting at Address.

  @param[in]   UserBuffer  For read operations, the destination buffer to store
                           the results. For write operations, the source buffer
                           to write data from.


  @retval EFI_SUCCESS              The data was read from or written to the PCI
                                   root bridge.

  @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER    Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a
                                   lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoIoWrite (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 UserAddress,
  IN     UINTN                                  Count,
  IN     VOID                                   *UserBuffer
  );

/**
  Enables a PCI driver to copy one region of PCI root bridge memory space to
  another region of PCI root bridge memory space.

  The CopyMem() function enables a PCI driver to copy one region of PCI root
  bridge memory space to another region of PCI root bridge memory space. This
  is especially useful for video scroll operation on a memory mapped video
  buffer.
  The memory operations are carried out exactly as requested. The caller is
  responsible for satisfying any alignment and memory width restrictions that a
  PCI root bridge on a platform might require.

  @param[in] This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
                         instance.

  @param[in] Width       Signifies the width of the memory operations.

  @param[in] DestAddress The destination address of the memory operation. The
                         caller is responsible for aligning the DestAddress if
                         required.

  @param[in] SrcAddress  The source address of the memory operation. The caller
                         is responsible for aligning the SrcAddress if
                         required.

  @param[in] Count       The number of memory operations to perform. Bytes
                         moved is Width size * Count, starting at DestAddress
                         and SrcAddress.


  @retval  EFI_SUCCESS             The data was copied from one memory region
                                   to another memory region.

  @retval  EFI_INVALID_PARAMETER   Width is invalid for this PCI root bridge.

  @retval  EFI_OUT_OF_RESOURCES    The request could not be completed due to a
                                   lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoCopyMem (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 DestAddress,
  IN     UINT64                                 SrcAddress,
  IN     UINTN                                  Count
  );

/**
  Enables a PCI driver to access PCI controller registers in a PCI root
  bridge's configuration space.

  The Pci.Read() and Pci.Write() functions enable a driver to access PCI
  configuration registers for a PCI controller.
  The PCI Configuration operations are carried out exactly as requested. The
  caller is responsible for any alignment and PCI configuration width issues
  that a PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operations.

  @param[in]   Address   The address within the PCI configuration space for the
                         PCI controller.

  @param[in]   Count     The number of PCI configuration operations to perform.
                         Bytes moved is Width size * Count, starting at
                         Address.

  @param[out]  Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.


  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPciRead (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  OUT    VOID                                   *Buffer
  );

/**
  Enables a PCI driver to access PCI controller registers in a PCI root
  bridge's configuration space.

  The Pci.Read() and Pci.Write() functions enable a driver to access PCI
  configuration registers for a PCI controller.
  The PCI Configuration operations are carried out exactly as requested. The
  caller is responsible for any alignment and PCI configuration width issues
  that a PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operations.

  @param[in]   Address   The address within the PCI configuration space for the
                         PCI controller.

  @param[in]   Count     The number of PCI configuration operations to perform.
                         Bytes moved is Width size * Count, starting at
                         Address.

  @param[in]   Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.


  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPciWrite (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  IN     VOID                                   *Buffer
  );

/**
  Provides the PCI controller-specific addresses required to access system
  memory from a DMA bus master.

  The Map() function provides the PCI controller specific addresses needed to
  access system memory. This function is used to map system memory for PCI bus
  master DMA accesses.

  @param[in]       This            A pointer to the
                                   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]       Operation       Indicates if the bus master is going to read
                                   or write to system memory.

  @param[in]       HostAddress     The system memory address to map to the PCI
                                   controller.

  @param[in, out]  NumberOfBytes   On input the number of bytes to map. On
                                   output the number of bytes that were mapped.

  @param[out]      DeviceAddress   The resulting map address for the bus master
                                   PCI controller to use to access the system
                                   memory's HostAddress.

  @param[out]      Mapping         The value to pass to Unmap() when the bus
                                   master DMA operation is complete.

  @retval EFI_SUCCESS            The range was mapped for the returned
                                 NumberOfBytes.

  @retval EFI_INVALID_PARAMETER  Operation is invalid.

  @retval EFI_INVALID_PARAMETER  HostAddress is NULL.

  @retval EFI_INVALID_PARAMETER  NumberOfBytes is NULL.

  @retval EFI_INVALID_PARAMETER  DeviceAddress is NULL.

  @retval EFI_INVALID_PARAMETER  Mapping is NULL.

  @retval EFI_UNSUPPORTED        The HostAddress cannot be mapped as a common
                                 buffer.

  @retval EFI_DEVICE_ERROR       The system hardware could not map the
                                 requested address.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoMap (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL            *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION  Operation,
  IN     VOID                                       *HostAddress,
  IN OUT UINTN                                      *NumberOfBytes,
  OUT    EFI_PHYSICAL_ADDRESS                       *DeviceAddress,
  OUT    VOID                                       **Mapping
  );

/**
  Completes the Map() operation and releases any corresponding resources.

  The Unmap() function completes the Map() operation and releases any
  corresponding resources.
  If the operation was an EfiPciOperationBusMasterWrite or
  EfiPciOperationBusMasterWrite64, the data is committed to the target system
  memory.
  Any resources used for the mapping are freed.

  @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in] Mapping   The mapping value returned from Map().

  @retval EFI_SUCCESS            The range was unmapped.

  @retval EFI_INVALID_PARAMETER  Mapping is not a value that was returned by
                                 Map().

  @retval EFI_DEVICE_ERROR       The data was not committed to the target
                                 system memory.
**/
EFI_STATUS
EFIAPI
RootBridgeIoUnmap (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN  VOID                             *Mapping
  );

/**
  Allocates pages that are suitable for an EfiPciOperationBusMasterCommonBuffer
  or EfiPciOperationBusMasterCommonBuffer64 mapping.

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param Type        This parameter is not used and must be ignored.

  @param MemoryType  The type of memory to allocate, EfiBootServicesData or
                     EfiRuntimeServicesData.

  @param Pages       The number of pages to allocate.

  @param HostAddress A pointer to store the base system memory address of the
                     allocated range.

  @param Attributes  The requested bit mask of attributes for the allocated
                     range. Only the attributes
                     EFI_PCI_ATTRIBUTE_MEMORY_WRITE_COMBINE,
                     EFI_PCI_ATTRIBUTE_MEMORY_CACHED, and
                     EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE may be used with this
                     function.

  @retval EFI_SUCCESS            The requested memory pages were allocated.

  @retval EFI_INVALID_PARAMETER  MemoryType is invalid.

  @retval EFI_INVALID_PARAMETER  HostAddress is NULL.

  @retval EFI_UNSUPPORTED        Attributes is unsupported. The only legal
                                 attribute bits are MEMORY_WRITE_COMBINE,
                                 MEMORY_CACHED, and DUAL_ADDRESS_CYCLE.

  @retval EFI_OUT_OF_RESOURCES   The memory pages could not be allocated.
**/
EFI_STATUS
EFIAPI
RootBridgeIoAllocateBuffer (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN  EFI_ALLOCATE_TYPE                Type,
  IN  EFI_MEMORY_TYPE                  MemoryType,
  IN  UINTN                            Pages,
  OUT VOID                             **HostAddress,
  IN  UINT64                           Attributes
  );

/**
  Frees memory that was allocated with AllocateBuffer().

  The FreeBuffer() function frees memory that was allocated with
  AllocateBuffer().

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param Pages       The number of pages to free.

  @param HostAddress The base system memory address of the allocated range.

  @retval EFI_SUCCESS            The requested memory pages were freed.

  @retval EFI_INVALID_PARAMETER  The memory range specified by HostAddress and
                                 Pages was not allocated with AllocateBuffer().
**/
EFI_STATUS
EFIAPI
RootBridgeIoFreeBuffer (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN  UINTN                            Pages,
  OUT VOID                             *HostAddress
  );

/**
  Flushes all PCI posted write transactions from a PCI host bridge to system
  memory.

  The Flush() function flushes any PCI posted write transactions from a PCI
  host bridge to system memory. Posted write transactions are generated by PCI
  bus masters when they perform write transactions to target addresses in
  system memory.
  This function does not flush posted write transactions from any PCI bridges.
  A PCI controller specific action must be taken to guarantee that the posted
  write transactions have been flushed from the PCI controller and from all the
  PCI bridges into the PCI host bridge. This is typically done with a PCI read
  transaction from the PCI controller prior to calling Flush().

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @retval EFI_SUCCESS        The PCI posted write transactions were flushed
                             from the PCI host bridge to system memory.

  @retval EFI_DEVICE_ERROR   The PCI posted write transactions were not flushed
                             from the PCI host bridge due to a hardware error.
**/
EFI_STATUS
EFIAPI
RootBridgeIoFlush (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This
  );

/**
  Gets the attributes that a PCI root bridge supports setting with
  SetAttributes(), and the attributes that a PCI root bridge is currently
  using.

  The GetAttributes() function returns the mask of attributes that this PCI
  root bridge supports and the mask of attributes that the PCI root bridge is
  currently using.

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param Supported   A pointer to the mask of attributes that this PCI root
                     bridge supports setting with SetAttributes().

  @param Attributes  A pointer to the mask of attributes that this PCI root
                     bridge is currently using.


  @retval  EFI_SUCCESS           If Supports is not NULL, then the attributes
                                 that the PCI root bridge supports is returned
                                 in Supports. If Attributes is not NULL, then
                                 the attributes that the PCI root bridge is
                                 currently using is returned in Attributes.

  @retval  EFI_INVALID_PARAMETER Both Supports and Attributes are NULL.
**/
EFI_STATUS
EFIAPI
RootBridgeIoGetAttributes (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  OUT UINT64                           *Supported,
  OUT UINT64                           *Attributes
  );

/**
  Sets attributes for a resource range on a PCI root bridge.

  The SetAttributes() function sets the attributes specified in Attributes for
  the PCI root bridge on the resource range specified by ResourceBase and
  ResourceLength. Since the granularity of setting these attributes may vary
  from resource type to resource type, and from platform to platform, the
  actual resource range and the one passed in by the caller may differ. As a
  result, this function may set the attributes specified by Attributes on a
  larger resource range than the caller requested. The actual range is returned
  in ResourceBase and ResourceLength. The caller is responsible for verifying
  that the actual range for which the attributes were set is acceptable.

  @param[in]       This            A pointer to the
                                   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]       Attributes      The mask of attributes to set. If the
                                   attribute bit MEMORY_WRITE_COMBINE,
                                   MEMORY_CACHED, or MEMORY_DISABLE is set,
                                   then the resource range is specified by
                                   ResourceBase and ResourceLength. If
                                   MEMORY_WRITE_COMBINE, MEMORY_CACHED, and
                                   MEMORY_DISABLE are not set, then
                                   ResourceBase and ResourceLength are ignored,
                                   and may be NULL.

  @param[in, out]  ResourceBase    A pointer to the base address of the
                                   resource range to be modified by the
                                   attributes specified by Attributes.

  @param[in, out]  ResourceLength  A pointer to the length of the resource
                                   range to be modified by the attributes
                                   specified by Attributes.

  @retval  EFI_SUCCESS     The current configuration of this PCI root bridge
                           was returned in Resources.

  @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge
                           could not be retrieved.

  @retval  EFI_INVALID_PARAMETER Invalid pointer of
                                 EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL

**/
EFI_STATUS
EFIAPI
RootBridgeIoSetAttributes (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN     UINT64                           Attributes,
  IN OUT UINT64                           *ResourceBase,
  IN OUT UINT64                           *ResourceLength
  );

/**
  Retrieves the current resource settings of this PCI root bridge in the form
  of a set of ACPI 2.0 resource descriptors.

  There are only two resource descriptor types from the ACPI Specification that
  may be used to describe the current resources allocated to a PCI root bridge.
  These are the QWORD Address Space Descriptor (ACPI 2.0 Section 6.4.3.5.1),
  and the End Tag (ACPI 2.0 Section 6.4.2.8). The QWORD Address Space
  Descriptor can describe memory, I/O, and bus number ranges for dynamic or
  fixed resources. The configuration of a PCI root bridge is described with one
  or more QWORD Address Space Descriptors followed by an End Tag.

  @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[out]  Resources   A pointer to the ACPI 2.0 resource descriptors that
                           describe the current configuration of this PCI root
                           bridge. The storage for the ACPI 2.0 resource
                           descriptors is allocated by this function. The
                           caller must treat the return buffer as read-only
                           data, and the buffer must not be freed by the
                           caller.

  @retval  EFI_SUCCESS     The current configuration of this PCI root bridge
                           was returned in Resources.

  @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge
                           could not be retrieved.

  @retval  EFI_INVALID_PARAMETER Invalid pointer of
                                 EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
**/
EFI_STATUS
EFIAPI
RootBridgeIoConfiguration (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  OUT    VOID                             **Resources
  );

//
// Memory Controller Pci Root Bridge Io Module Variables
//
EFI_METRONOME_ARCH_PROTOCOL *mMetronome;

//
// Lookup table for increment values based on transfer widths
//
UINT8 mInStride[] = {
  1, // EfiPciWidthUint8
  2, // EfiPciWidthUint16
  4, // EfiPciWidthUint32
  8, // EfiPciWidthUint64
  0, // EfiPciWidthFifoUint8
  0, // EfiPciWidthFifoUint16
  0, // EfiPciWidthFifoUint32
  0, // EfiPciWidthFifoUint64
  1, // EfiPciWidthFillUint8
  2, // EfiPciWidthFillUint16
  4, // EfiPciWidthFillUint32
  8  // EfiPciWidthFillUint64
};

//
// Lookup table for increment values based on transfer widths
//
UINT8 mOutStride[] = {
  1, // EfiPciWidthUint8
  2, // EfiPciWidthUint16
  4, // EfiPciWidthUint32
  8, // EfiPciWidthUint64
  1, // EfiPciWidthFifoUint8
  2, // EfiPciWidthFifoUint16
  4, // EfiPciWidthFifoUint32
  8, // EfiPciWidthFifoUint64
  0, // EfiPciWidthFillUint8
  0, // EfiPciWidthFillUint16
  0, // EfiPciWidthFillUint32
  0  // EfiPciWidthFillUint64
};

/**
  Construct the Pci Root Bridge Io protocol

  @param Protocol         Point to protocol instance

  @param HostBridgeHandle Handle of host bridge

  @param Attri            Attribute of host bridge

  @param ResAperture      ResourceAperture for host bridge

  @retval EFI_SUCCESS Success to initialize the Pci Root Bridge.
**/
EFI_STATUS
RootBridgeConstructor (
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL    *Protocol,
  IN EFI_HANDLE                         HostBridgeHandle,
  IN UINT64                             Attri,
  IN PCI_ROOT_BRIDGE_RESOURCE_APERTURE  *ResAperture
  )
{
  EFI_STATUS                        Status;
  PCI_ROOT_BRIDGE_INSTANCE          *PrivateData;
  PCI_RESOURCE_TYPE                 Index;

  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS (Protocol);

  //
  // The host to pci bridge, the host memory and io addresses are
  // direct mapped to pci addresses, so no need translate, set bases to 0.
  //
  PrivateData->MemBase = ResAperture->MemBase;
  PrivateData->IoBase  = ResAperture->IoBase;

  //
  // The host bridge only supports 32bit addressing for memory
  // and standard IA32 16bit io
  //
  PrivateData->MemLimit = ResAperture->MemLimit;
  PrivateData->IoLimit  = ResAperture->IoLimit;

  //
  // Bus Aperture for this Root Bridge (Possible Range)
  //
  PrivateData->BusBase  = ResAperture->BusBase;
  PrivateData->BusLimit = ResAperture->BusLimit;

  //
  // Specific for this chipset
  //
  for (Index = TypeIo; Index < TypeMax; Index++) {
    PrivateData->ResAllocNode[Index].Type      = Index;
    PrivateData->ResAllocNode[Index].Base      = 0;
    PrivateData->ResAllocNode[Index].Length    = 0;
    PrivateData->ResAllocNode[Index].Status    = ResNone;
  }

  PrivateData->RootBridgeAttrib = Attri;

  PrivateData->Supports    = EFI_PCI_ATTRIBUTE_IDE_PRIMARY_IO |
                             EFI_PCI_ATTRIBUTE_IDE_SECONDARY_IO |
                             EFI_PCI_ATTRIBUTE_ISA_IO_16 |
                             EFI_PCI_ATTRIBUTE_ISA_MOTHERBOARD_IO |
                             EFI_PCI_ATTRIBUTE_VGA_MEMORY |
                             EFI_PCI_ATTRIBUTE_VGA_IO_16  |
                             EFI_PCI_ATTRIBUTE_VGA_PALETTE_IO_16;
  PrivateData->Attributes  = PrivateData->Supports;

  Protocol->ParentHandle   = HostBridgeHandle;

  Protocol->PollMem        = RootBridgeIoPollMem;
  Protocol->PollIo         = RootBridgeIoPollIo;

  Protocol->Mem.Read       = RootBridgeIoMemRead;
  Protocol->Mem.Write      = RootBridgeIoMemWrite;

  Protocol->Io.Read        = RootBridgeIoIoRead;
  Protocol->Io.Write       = RootBridgeIoIoWrite;

  Protocol->CopyMem        = RootBridgeIoCopyMem;

  Protocol->Pci.Read       = RootBridgeIoPciRead;
  Protocol->Pci.Write      = RootBridgeIoPciWrite;

  Protocol->Map            = RootBridgeIoMap;
  Protocol->Unmap          = RootBridgeIoUnmap;

  Protocol->AllocateBuffer = RootBridgeIoAllocateBuffer;
  Protocol->FreeBuffer     = RootBridgeIoFreeBuffer;

  Protocol->Flush          = RootBridgeIoFlush;

  Protocol->GetAttributes  = RootBridgeIoGetAttributes;
  Protocol->SetAttributes  = RootBridgeIoSetAttributes;

  Protocol->Configuration  = RootBridgeIoConfiguration;

  Protocol->SegmentNumber  = 0;

  Status = gBS->LocateProtocol (&gEfiMetronomeArchProtocolGuid, NULL,
                  (VOID **)&mMetronome);
  ASSERT_EFI_ERROR (Status);

  return EFI_SUCCESS;
}

/**
  Check parameters for IO,MMIO,PCI read/write services of PCI Root Bridge IO.

  The I/O operations are carried out exactly as requested. The caller is
  responsible for satisfying any alignment and I/O width restrictions that a PI
  System on a platform might require. For example on some platforms, width
  requests of EfiCpuIoWidthUint64 do not work. Misaligned buffers, on the other
  hand, will be handled by the driver.

  @param[in] This           A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in] OperationType  I/O operation type: IO/MMIO/PCI.

  @param[in] Width          Signifies the width of the I/O or Memory operation.

  @param[in] Address        The base address of the I/O operation.

  @param[in] Count          The number of I/O operations to perform. The number
                            of bytes moved is Width size * Count, starting at
                            Address.

  @param[in] Buffer         For read operations, the destination buffer to
                            store the results. For write operations, the source
                            buffer from which to write data.

  @retval EFI_SUCCESS            The parameters for this request pass the
                                 checks.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PI system.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_UNSUPPORTED        The Buffer is not aligned for the given Width.

  @retval EFI_UNSUPPORTED        The address range specified by Address, Width,
                                 and Count is not valid for this PI system.
**/
EFI_STATUS
RootBridgeIoCheckParameter (
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN OPERATION_TYPE                         OperationType,
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN UINT64                                 Address,
  IN UINTN                                  Count,
  IN VOID                                   *Buffer
  )
{
  PCI_ROOT_BRIDGE_INSTANCE                     *PrivateData;
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS  *PciRbAddr;
  UINT64                                       MaxCount;
  UINT64                                       Base;
  UINT64                                       Limit;

  //
  // Check to see if Buffer is NULL
  //
  if (Buffer == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Check to see if Width is in the valid range
  //
  if ((UINT32)Width >= EfiPciWidthMaximum) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // For FIFO type, the target address won't increase during the access,
  // so treat Count as 1
  //
  if (Width >= EfiPciWidthFifoUint8 && Width <= EfiPciWidthFifoUint64) {
    Count = 1;
  }

  //
  // Check to see if Width is in the valid range for I/O Port operations
  //
  Width = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);
  if ((OperationType != MemOperation) && (Width == EfiPciWidthUint64)) {
    ASSERT (FALSE);
    return EFI_INVALID_PARAMETER;
  }

  //
  // Check to see if Address is aligned
  //
  if ((Address & (UINT64)(mInStride[Width] - 1)) != 0) {
    return EFI_UNSUPPORTED;
  }

  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS (This);

  //
  // Check to see if any address associated with this transfer exceeds the
  // maximum allowed address.  The maximum address implied by the parameters
  // passed in is Address + Size * Count.  If the following condition is met,
  // then the transfer is not supported.
  //
  //    Address + Size * Count > Limit + 1
  //
  // Since Limit can be the maximum integer value supported by the CPU and
  // Count can also be the maximum integer value supported by the CPU, this
  // range check must be adjusted to avoid all oveflow conditions.
  //
  // The following form of the range check is equivalent but assumes that
  // Limit is of the form (2^n - 1).
  //
  if (OperationType == IoOperation) {
    Base = PrivateData->IoBase;
    Limit = PrivateData->IoLimit;
  } else if (OperationType == MemOperation) {
    Base = PrivateData->MemBase;
    Limit = PrivateData->MemLimit;
  } else {
    PciRbAddr = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS*) &Address;
    if (PciRbAddr->Bus < PrivateData->BusBase ||
        PciRbAddr->Bus > PrivateData->BusLimit) {
      return EFI_INVALID_PARAMETER;
    }

    if (PciRbAddr->Device > MAX_PCI_DEVICE_NUMBER ||
        PciRbAddr->Function > MAX_PCI_FUNCTION_NUMBER) {
      return EFI_INVALID_PARAMETER;
    }

    if (PciRbAddr->ExtendedRegister != 0) {
      Address = PciRbAddr->ExtendedRegister;
    } else {
      Address = PciRbAddr->Register;
    }
    Base = 0;
    Limit = MAX_PCI_REG_ADDRESS;
  }

  if (Address < Base) {
      return EFI_INVALID_PARAMETER;
  }

  if (Count == 0) {
    if (Address > Limit) {
      return EFI_UNSUPPORTED;
    }
  } else {
    MaxCount = RShiftU64 (Limit, Width);
    if (MaxCount < (Count - 1)) {
      return EFI_UNSUPPORTED;
    }
    if (Address > LShiftU64 (MaxCount - Count + 1, Width)) {
      return EFI_UNSUPPORTED;
    }
  }

  return EFI_SUCCESS;
}

/**
  Internal help function for read and write memory space.

  @param[in]   This          A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Write         Switch value for Read or Write.

  @param[in]   Width         Signifies the width of the memory operations.

  @param[in]   UserAddress   The address within the PCI configuration space for
                             the PCI controller.

  @param[in]   Count         The number of PCI configuration operations to
                             perform. Bytes moved is Width size * Count,
                             starting at Address.

  @param[in, out] UserBuffer For read operations, the destination buffer to
                             store the results. For write operations, the
                             source buffer to write data from.

  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
RootBridgeIoMemRW (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     BOOLEAN                                Write,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  IN OUT VOID                                   *Buffer
  )
{
  EFI_STATUS                             Status;
  UINT8                                  InStride;
  UINT8                                  OutStride;
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  OperationWidth;
  UINT8                                  *Uint8Buffer;

  Status = RootBridgeIoCheckParameter (This, MemOperation, Width, Address,
             Count, Buffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  InStride = mInStride[Width];
  OutStride = mOutStride[Width];
  OperationWidth = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);
  for (Uint8Buffer = Buffer;
       Count > 0;
       Address += InStride, Uint8Buffer += OutStride, Count--) {
    if (Write) {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          MmioWrite8 ((UINTN)Address, *Uint8Buffer);
          break;
        case EfiPciWidthUint16:
          MmioWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
          break;
        case EfiPciWidthUint32:
          MmioWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
          break;
        case EfiPciWidthUint64:
          MmioWrite64 ((UINTN)Address, *((UINT64 *)Uint8Buffer));
          break;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    } else {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          *Uint8Buffer = MmioRead8 ((UINTN)Address);
          break;
        case EfiPciWidthUint16:
          *((UINT16 *)Uint8Buffer) = MmioRead16 ((UINTN)Address);
          break;
        case EfiPciWidthUint32:
          *((UINT32 *)Uint8Buffer) = MmioRead32 ((UINTN)Address);
          break;
        case EfiPciWidthUint64:
          *((UINT64 *)Uint8Buffer) = MmioRead64 ((UINTN)Address);
          break;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    }
  }
  return EFI_SUCCESS;
}

/**
  Internal help function for read and write IO space.

  @param[in]   This          A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Write         Switch value for Read or Write.

  @param[in]   Width         Signifies the width of the memory operations.

  @param[in]   UserAddress   The address within the PCI configuration space for
                             the PCI controller.

  @param[in]   Count         The number of PCI configuration operations to
                             perform. Bytes moved is Width size * Count,
                             starting at Address.

  @param[in, out] UserBuffer For read operations, the destination buffer to
                             store the results. For write operations, the
                             source buffer to write data from.


  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
RootBridgeIoIoRW (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     BOOLEAN                                Write,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  IN OUT VOID                                   *Buffer
  )
{
  EFI_STATUS                             Status;
  UINT8                                  InStride;
  UINT8                                  OutStride;
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  OperationWidth;
  UINT8                                  *Uint8Buffer;

  Status = RootBridgeIoCheckParameter (This, IoOperation, Width, Address,
             Count, Buffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  InStride = mInStride[Width];
  OutStride = mOutStride[Width];
  OperationWidth = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);

#if defined (MDE_CPU_IA32) || defined (MDE_CPU_X64)
  if (InStride == 0) {
    if (Write) {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          IoWriteFifo8 ((UINTN) Address, Count, Buffer);
          return EFI_SUCCESS;
        case EfiPciWidthUint16:
          IoWriteFifo16 ((UINTN) Address, Count, Buffer);
          return EFI_SUCCESS;
        case EfiPciWidthUint32:
          IoWriteFifo32 ((UINTN) Address, Count, Buffer);
          return EFI_SUCCESS;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    } else {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          IoReadFifo8 ((UINTN) Address, Count, Buffer);
          return EFI_SUCCESS;
        case EfiPciWidthUint16:
          IoReadFifo16 ((UINTN) Address, Count, Buffer);
          return EFI_SUCCESS;
        case EfiPciWidthUint32:
          IoReadFifo32 ((UINTN) Address, Count, Buffer);
          return EFI_SUCCESS;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    }
  }
#endif

  for (Uint8Buffer = Buffer;
       Count > 0;
       Address += InStride, Uint8Buffer += OutStride, Count--) {
    if (Write) {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          IoWrite8 ((UINTN)Address, *Uint8Buffer);
          break;
        case EfiPciWidthUint16:
          IoWrite16 ((UINTN)Address, *((UINT16 *)Uint8Buffer));
          break;
        case EfiPciWidthUint32:
          IoWrite32 ((UINTN)Address, *((UINT32 *)Uint8Buffer));
          break;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    } else {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          *Uint8Buffer = IoRead8 ((UINTN)Address);
          break;
        case EfiPciWidthUint16:
          *((UINT16 *)Uint8Buffer) = IoRead16 ((UINTN)Address);
          break;
        case EfiPciWidthUint32:
          *((UINT32 *)Uint8Buffer) = IoRead32 ((UINTN)Address);
          break;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    }
  }
  return EFI_SUCCESS;
}

/**
  Internal help function for read and write PCI configuration space.

  @param[in]   This          A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Write         Switch value for Read or Write.

  @param[in]   Width         Signifies the width of the memory operations.

  @param[in]   UserAddress   The address within the PCI configuration space for
                             the PCI controller.

  @param[in]   Count         The number of PCI configuration operations to
                             perform. Bytes moved is Width size * Count,
                             starting at Address.

  @param[in, out] UserBuffer For read operations, the destination buffer to
                             store the results. For write operations, the
                             source buffer to write data from.


  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
RootBridgeIoPciRW (
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN BOOLEAN                                Write,
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN UINT64                                 Address,
  IN UINTN                                  Count,
  IN OUT VOID                               *Buffer
  )
{
  EFI_STATUS                                   Status;
  UINT8                                        InStride;
  UINT8                                        OutStride;
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH        OperationWidth;
  UINT8                                        *Uint8Buffer;
  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS  *PciRbAddr;
  UINTN                                        PcieRegAddr;

  Status = RootBridgeIoCheckParameter (This, PciOperation, Width, Address,
             Count, Buffer);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  PciRbAddr = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_PCI_ADDRESS*) &Address;

  PcieRegAddr = (UINTN) PCI_LIB_ADDRESS (
                          PciRbAddr->Bus,
                          PciRbAddr->Device,
                          PciRbAddr->Function,
                          (PciRbAddr->ExtendedRegister != 0) ? \
                            PciRbAddr->ExtendedRegister :
                            PciRbAddr->Register
                          );

  InStride = mInStride[Width];
  OutStride = mOutStride[Width];
  OperationWidth = (EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH) (Width & 0x03);
  for (Uint8Buffer = Buffer;
       Count > 0;
       PcieRegAddr += InStride, Uint8Buffer += OutStride, Count--) {
    if (Write) {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          PciWrite8 (PcieRegAddr, *Uint8Buffer);
          break;
        case EfiPciWidthUint16:
          PciWrite16 (PcieRegAddr, *((UINT16 *)Uint8Buffer));
          break;
        case EfiPciWidthUint32:
          PciWrite32 (PcieRegAddr, *((UINT32 *)Uint8Buffer));
          break;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    } else {
      switch (OperationWidth) {
        case EfiPciWidthUint8:
          *Uint8Buffer = PciRead8 (PcieRegAddr);
          break;
        case EfiPciWidthUint16:
          *((UINT16 *)Uint8Buffer) = PciRead16 (PcieRegAddr);
          break;
        case EfiPciWidthUint32:
          *((UINT32 *)Uint8Buffer) = PciRead32 (PcieRegAddr);
          break;
        default:
          //
          // The RootBridgeIoCheckParameter call above will ensure that this
          // path is not taken.
          //
          ASSERT (FALSE);
          break;
      }
    }
  }

  return EFI_SUCCESS;
}

/**
  Polls an address in memory mapped I/O space until an exit condition is met,
  or a timeout occurs.

  This function provides a standard way to poll a PCI memory location. A PCI
  memory read operation is performed at the PCI memory address specified by
  Address for the width specified by Width. The result of this PCI memory read
  operation is stored in Result. This PCI memory read operation is repeated
  until either a timeout of Delay 100 ns units has expired, or (Result & Mask)
  is equal to Value.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operations.

  @param[in]   Address   The base address of the memory operations. The caller
                         is responsible for aligning Address if required.

  @param[in]   Mask      Mask used for the polling criteria. Bytes above Width
                         in Mask are ignored. The bits in the bytes below Width
                         which are zero in Mask are ignored when polling the
                         memory address.

  @param[in]   Value     The comparison value used for the polling exit
                         criteria.

  @param[in]   Delay     The number of 100 ns units to poll. Note that timer
                         available may be of poorer granularity.

  @param[out]  Result    Pointer to the last value read from the memory
                         location.

  @retval EFI_SUCCESS            The last data returned from the access matched
                                 the poll exit criteria.

  @retval EFI_INVALID_PARAMETER  Width is invalid.

  @retval EFI_INVALID_PARAMETER  Result is NULL.

  @retval EFI_TIMEOUT            Delay expired before a match occurred.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPollMem (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN  UINT64                                 Address,
  IN  UINT64                                 Mask,
  IN  UINT64                                 Value,
  IN  UINT64                                 Delay,
  OUT UINT64                                 *Result
  )
{
  EFI_STATUS  Status;
  UINT64      NumberOfTicks;
  UINT32      Remainder;

  if (Result == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if ((UINT32)Width > EfiPciWidthUint64) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // No matter what, always do a single poll.
  //
  Status = This->Mem.Read (This, Width, Address, 1, Result);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if ((*Result & Mask) == Value) {
    return EFI_SUCCESS;
  }

  if (Delay == 0) {
    return EFI_SUCCESS;

  } else {

    //
    // Determine the proper # of metronome ticks to wait for polling the
    // location.  The nuber of ticks is Roundup (Delay /
    // mMetronome->TickPeriod)+1
    // The "+1" to account for the possibility of the first tick being short
    // because we started in the middle of a tick.
    //
    // BugBug: overriding mMetronome->TickPeriod with UINT32 until Metronome
    // protocol definition is updated.
    //
    NumberOfTicks = DivU64x32Remainder (Delay, (UINT32) mMetronome->TickPeriod,
                      &Remainder);
    if (Remainder != 0) {
      NumberOfTicks += 1;
    }
    NumberOfTicks += 1;

    while (NumberOfTicks != 0) {

      mMetronome->WaitForTick (mMetronome, 1);

      Status = This->Mem.Read (This, Width, Address, 1, Result);
      if (EFI_ERROR (Status)) {
        return Status;
      }

      if ((*Result & Mask) == Value) {
        return EFI_SUCCESS;
      }

      NumberOfTicks -= 1;
    }
  }
  return EFI_TIMEOUT;
}

/**
  Reads from the I/O space of a PCI Root Bridge. Returns when either the
  polling exit criteria is satisfied or after a defined duration.

  This function provides a standard way to poll a PCI I/O location. A PCI I/O
  read operation is performed at the PCI I/O address specified by Address for
  the width specified by Width.
  The result of this PCI I/O read operation is stored in Result. This PCI I/O
  read operation is repeated until either a timeout of Delay 100 ns units has
  expired, or (Result & Mask) is equal to Value.

  @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in] Width     Signifies the width of the I/O operations.

  @param[in] Address   The base address of the I/O operations. The caller is
                       responsible for aligning Address if required.

  @param[in] Mask      Mask used for the polling criteria. Bytes above Width in
                       Mask are ignored. The bits in the bytes below Width
                       which are zero in Mask are ignored when polling the I/O
                       address.

  @param[in] Value     The comparison value used for the polling exit criteria.

  @param[in] Delay     The number of 100 ns units to poll. Note that timer
                       available may be of poorer granularity.

  @param[out] Result   Pointer to the last value read from the memory location.

  @retval EFI_SUCCESS            The last data returned from the access matched
                                 the poll exit criteria.

  @retval EFI_INVALID_PARAMETER  Width is invalid.

  @retval EFI_INVALID_PARAMETER  Result is NULL.

  @retval EFI_TIMEOUT            Delay expired before a match occurred.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPollIo (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN  UINT64                                 Address,
  IN  UINT64                                 Mask,
  IN  UINT64                                 Value,
  IN  UINT64                                 Delay,
  OUT UINT64                                 *Result
  )
{
  EFI_STATUS  Status;
  UINT64      NumberOfTicks;
  UINT32      Remainder;

  //
  // No matter what, always do a single poll.
  //

  if (Result == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if ((UINT32)Width > EfiPciWidthUint64) {
    return EFI_INVALID_PARAMETER;
  }

  Status = This->Io.Read (This, Width, Address, 1, Result);
  if (EFI_ERROR (Status)) {
    return Status;
  }
  if ((*Result & Mask) == Value) {
    return EFI_SUCCESS;
  }

  if (Delay == 0) {
    return EFI_SUCCESS;

  } else {

    //
    // Determine the proper # of metronome ticks to wait for polling the
    // location.  The number of ticks is Roundup (Delay /
    // mMetronome->TickPeriod)+1
    // The "+1" to account for the possibility of the first tick being short
    // because we started in the middle of a tick.
    //
    NumberOfTicks = DivU64x32Remainder (Delay, (UINT32)mMetronome->TickPeriod,
                      &Remainder);
    if (Remainder != 0) {
      NumberOfTicks += 1;
    }
    NumberOfTicks += 1;

    while (NumberOfTicks != 0) {

      mMetronome->WaitForTick (mMetronome, 1);

      Status = This->Io.Read (This, Width, Address, 1, Result);
      if (EFI_ERROR (Status)) {
        return Status;
      }

      if ((*Result & Mask) == Value) {
        return EFI_SUCCESS;
      }

      NumberOfTicks -= 1;
    }
  }
  return EFI_TIMEOUT;
}

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge memory space.

  The Mem.Read(), and Mem.Write() functions enable a driver to access PCI
  controller registers in the PCI root bridge memory space.
  The memory operations are carried out exactly as requested. The caller is
  responsible for satisfying any alignment and memory width restrictions that a
  PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operation.

  @param[in]   Address   The base address of the memory operation. The caller
                         is responsible for aligning the Address if required.

  @param[in]   Count     The number of memory operations to perform. Bytes
                         moved is Width size * Count, starting at Address.

  @param[out]  Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.

  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoMemRead (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  OUT    VOID                                   *Buffer
  )
{
  return RootBridgeIoMemRW (This, FALSE, Width, Address, Count, Buffer);
}

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge memory space.

  The Mem.Read(), and Mem.Write() functions enable a driver to access PCI
  controller registers in the PCI root bridge memory space.
  The memory operations are carried out exactly as requested. The caller is
  responsible for satisfying any alignment and memory width restrictions that a
  PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operation.

  @param[in]   Address   The base address of the memory operation. The caller
                         is responsible for aligning the Address if required.

  @param[in]   Count     The number of memory operations to perform. Bytes
                         moved is Width size * Count, starting at Address.

  @param[in]   Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.

  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoMemWrite (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  IN     VOID                                   *Buffer
  )
{
  return RootBridgeIoMemRW (This, TRUE, Width, Address, Count, Buffer);
}

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge I/O space.

  @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width       Signifies the width of the memory operations.

  @param[in]   Address     The base address of the I/O operation. The caller is
                           responsible for aligning the Address if required.

  @param[in]   Count       The number of I/O operations to perform. Bytes moved
                           is Width size * Count, starting at Address.

  @param[out]  Buffer      For read operations, the destination buffer to store
                           the results. For write operations, the source buffer
                           to write data from.


  @retval EFI_SUCCESS              The data was read from or written to the PCI
                                   root bridge.

  @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER    Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a
                                   lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoIoRead (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN     UINT64                                 Address,
  IN     UINTN                                  Count,
  OUT    VOID                                   *Buffer
  )
{
  return RootBridgeIoIoRW (This, FALSE, Width, Address, Count, Buffer);
}

/**
  Enables a PCI driver to access PCI controller registers in the PCI root
  bridge I/O space.

  @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width       Signifies the width of the memory operations.

  @param[in]   Address     The base address of the I/O operation. The caller is
                           responsible for aligning the Address if required.

  @param[in]   Count       The number of I/O operations to perform. Bytes moved
                           is Width size * Count, starting at Address.

  @param[in]   Buffer      For read operations, the destination buffer to store
                           the results. For write operations, the source buffer
                           to write data from.

  @retval EFI_SUCCESS              The data was read from or written to the PCI
                                   root bridge.

  @retval EFI_INVALID_PARAMETER    Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER    Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a
                                   lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoIoWrite (
  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL         *This,
  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH   Width,
  IN       UINT64                                  Address,
  IN       UINTN                                   Count,
  IN       VOID                                    *Buffer
  )
{
  return RootBridgeIoIoRW (This, TRUE, Width, Address, Count, Buffer);
}

/**
  Enables a PCI driver to copy one region of PCI root bridge memory space to
  another region of PCI root bridge memory space.

  The CopyMem() function enables a PCI driver to copy one region of PCI root
  bridge memory space to another region of PCI root bridge memory space. This
  is especially useful for video scroll operation on a memory mapped video
  buffer.
  The memory operations are carried out exactly as requested. The caller is
  responsible for satisfying any alignment and memory width restrictions that a
  PCI root bridge on a platform might require.

  @param[in] This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
                         instance.

  @param[in] Width       Signifies the width of the memory operations.

  @param[in] DestAddress The destination address of the memory operation. The
                         caller is responsible for aligning the DestAddress if
                         required.

  @param[in] SrcAddress  The source address of the memory operation. The caller
                         is responsible for aligning the SrcAddress if
                         required.

  @param[in] Count       The number of memory operations to perform. Bytes
                         moved is Width size * Count, starting at DestAddress
                         and SrcAddress.

  @retval  EFI_SUCCESS             The data was copied from one memory region
                                   to another memory region.

  @retval  EFI_INVALID_PARAMETER   Width is invalid for this PCI root bridge.

  @retval  EFI_OUT_OF_RESOURCES    The request could not be completed due to a
                                   lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoCopyMem (
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL              *This,
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH        Width,
  IN UINT64                                       DestAddress,
  IN UINT64                                       SrcAddress,
  IN UINTN                                        Count
  )
{
  EFI_STATUS  Status;
  BOOLEAN     Direction;
  UINTN       Stride;
  UINTN       Index;
  UINT64      Result;

  if ((UINT32)Width > EfiPciWidthUint64) {
    return EFI_INVALID_PARAMETER;
  }

  if (DestAddress == SrcAddress) {
    return EFI_SUCCESS;
  }

  Stride = (UINTN)(1 << Width);

  Direction = TRUE;
  if ((DestAddress > SrcAddress) &&
      (DestAddress < (SrcAddress + Count * Stride))) {
    Direction   = FALSE;
    SrcAddress  = SrcAddress  + (Count-1) * Stride;
    DestAddress = DestAddress + (Count-1) * Stride;
  }

  for (Index = 0;Index < Count;Index++) {
    Status = RootBridgeIoMemRead (
               This,
               Width,
               SrcAddress,
               1,
               &Result
               );
    if (EFI_ERROR (Status)) {
      return Status;
    }
    Status = RootBridgeIoMemWrite (
               This,
               Width,
               DestAddress,
               1,
               &Result
               );
    if (EFI_ERROR (Status)) {
      return Status;
    }
    if (Direction) {
      SrcAddress  += Stride;
      DestAddress += Stride;
    } else {
      SrcAddress  -= Stride;
      DestAddress -= Stride;
    }
  }
  return EFI_SUCCESS;
}

/**
  Enables a PCI driver to access PCI controller registers in a PCI root
  bridge's configuration space.

  The Pci.Read() and Pci.Write() functions enable a driver to access PCI
  configuration registers for a PCI controller.
  The PCI Configuration operations are carried out exactly as requested. The
  caller is responsible for any alignment and PCI configuration width issues
  that a PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operations.

  @param[in]   Address   The address within the PCI configuration space for the
                         PCI controller.

  @param[in]   Count     The number of PCI configuration operations to perform.
                         Bytes moved is Width size * Count, starting at
                         Address.

  @param[out]  Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.

  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPciRead (
  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN       UINT64                                 Address,
  IN       UINTN                                  Count,
  OUT      VOID                                   *Buffer
  )
{
  return RootBridgeIoPciRW (This, FALSE, Width, Address, Count, Buffer);
}

/**
  Enables a PCI driver to access PCI controller registers in a PCI root
  bridge's configuration space.

  The Pci.Read() and Pci.Write() functions enable a driver to access PCI
  configuration registers for a PCI controller.
  The PCI Configuration operations are carried out exactly as requested. The
  caller is responsible for any alignment and PCI configuration width issues
  that a PCI Root Bridge on a platform might require.

  @param[in]   This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]   Width     Signifies the width of the memory operations.

  @param[in]   Address   The address within the PCI configuration space for the
                         PCI controller.

  @param[in]   Count     The number of PCI configuration operations to perform.
                         Bytes moved is Width size * Count, starting at
                         Address.

  @param[in]   Buffer    For read operations, the destination buffer to store
                         the results. For write operations, the source buffer
                         to write data from.

  @retval EFI_SUCCESS            The data was read from or written to the PCI
                                 root bridge.

  @retval EFI_INVALID_PARAMETER  Width is invalid for this PCI root bridge.

  @retval EFI_INVALID_PARAMETER  Buffer is NULL.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoPciWrite (
  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL        *This,
  IN       EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_WIDTH  Width,
  IN       UINT64                                 Address,
  IN       UINTN                                  Count,
  IN       VOID                                   *Buffer
  )
{
  return RootBridgeIoPciRW (This, TRUE, Width, Address, Count, Buffer);
}

/**
  Provides the PCI controller-specific addresses required to access system
  memory from a DMA bus master.

  The Map() function provides the PCI controller specific addresses needed to
  access system memory. This function is used to map system memory for PCI bus
  master DMA accesses.

  @param[in]       This            A pointer to the
                                   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]       Operation       Indicates if the bus master is going to read
                                   or write to system memory.

  @param[in]       HostAddress     The system memory address to map to the PCI
                                   controller.

  @param[in, out]  NumberOfBytes   On input the number of bytes to map. On
                                   output the number of bytes that were mapped.

  @param[out]      DeviceAddress   The resulting map address for the bus master
                                   PCI controller to use to access the system
                                   memory's HostAddress.

  @param[out]      Mapping         The value to pass to Unmap() when the bus
                                   master DMA operation is complete.

  @retval EFI_SUCCESS            The range was mapped for the returned
                                 NumberOfBytes.

  @retval EFI_INVALID_PARAMETER  Operation is invalid.

  @retval EFI_INVALID_PARAMETER  HostAddress is NULL.

  @retval EFI_INVALID_PARAMETER  NumberOfBytes is NULL.

  @retval EFI_INVALID_PARAMETER  DeviceAddress is NULL.

  @retval EFI_INVALID_PARAMETER  Mapping is NULL.

  @retval EFI_UNSUPPORTED        The HostAddress cannot be mapped as a common
                                 buffer.

  @retval EFI_DEVICE_ERROR       The system hardware could not map the
                                 requested address.

  @retval EFI_OUT_OF_RESOURCES   The request could not be completed due to a
                                 lack of resources.
**/
EFI_STATUS
EFIAPI
RootBridgeIoMap (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL            *This,
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL_OPERATION  Operation,
  IN     VOID                                       *HostAddress,
  IN OUT UINTN                                      *NumberOfBytes,
  OUT    EFI_PHYSICAL_ADDRESS                       *DeviceAddress,
  OUT    VOID                                       **Mapping
  )
{
  EFI_STATUS            Status;
  EFI_PHYSICAL_ADDRESS  PhysicalAddress;
  MAP_INFO              *MapInfo;

  if (HostAddress == NULL || NumberOfBytes == NULL || DeviceAddress == NULL ||
      Mapping == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Initialize the return values to their defaults
  //
  *Mapping = NULL;

  //
  // Make sure that Operation is valid
  //
  if ((UINT32)Operation >= EfiPciOperationMaximum) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Most PCAT like chipsets can not handle performing DMA above 4GB.
  // If any part of the DMA transfer being mapped is above 4GB, then
  // map the DMA transfer to a buffer below 4GB.
  //
  PhysicalAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress;
  if ((PhysicalAddress + *NumberOfBytes) > 0x100000000ULL) {

    //
    // Common Buffer operations can not be remapped.  If the common buffer
    // if above 4GB, then it is not possible to generate a mapping, so return
    // an error.
    //
    if (Operation == EfiPciOperationBusMasterCommonBuffer ||
        Operation == EfiPciOperationBusMasterCommonBuffer64) {
      return EFI_UNSUPPORTED;
    }

    //
    // Allocate a MAP_INFO structure to remember the mapping when Unmap() is
    // called later.
    //
    Status = gBS->AllocatePool (
                    EfiBootServicesData,
                    sizeof(MAP_INFO),
                    (VOID **)&MapInfo
                    );
    if (EFI_ERROR (Status)) {
      *NumberOfBytes = 0;
      return Status;
    }

    //
    // Return a pointer to the MAP_INFO structure in Mapping
    //
    *Mapping = MapInfo;

    //
    // Initialize the MAP_INFO structure
    //
    MapInfo->Operation         = Operation;
    MapInfo->NumberOfBytes     = *NumberOfBytes;
    MapInfo->NumberOfPages     = EFI_SIZE_TO_PAGES(*NumberOfBytes);
    MapInfo->HostAddress       = PhysicalAddress;
    MapInfo->MappedHostAddress = 0x00000000ffffffff;

    //
    // Allocate a buffer below 4GB to map the transfer to.
    //
    Status = gBS->AllocatePages (
                    AllocateMaxAddress,
                    EfiBootServicesData,
                    MapInfo->NumberOfPages,
                    &MapInfo->MappedHostAddress
                    );
    if (EFI_ERROR (Status)) {
      gBS->FreePool (MapInfo);
      *NumberOfBytes = 0;
      return Status;
    }

    //
    // If this is a read operation from the Bus Master's point of view,
    // then copy the contents of the real buffer into the mapped buffer
    // so the Bus Master can read the contents of the real buffer.
    //
    if (Operation == EfiPciOperationBusMasterRead ||
        Operation == EfiPciOperationBusMasterRead64) {
      CopyMem (
        (VOID *)(UINTN)MapInfo->MappedHostAddress,
        (VOID *)(UINTN)MapInfo->HostAddress,
        MapInfo->NumberOfBytes
        );
    }

    //
    // The DeviceAddress is the address of the maped buffer below 4GB
    //
    *DeviceAddress = MapInfo->MappedHostAddress;
  } else {
    //
    // The transfer is below 4GB, so the DeviceAddress is simply the
    // HostAddress
    //
    *DeviceAddress = PhysicalAddress;
  }

  return EFI_SUCCESS;
}

/**
  Completes the Map() operation and releases any corresponding resources.

  The Unmap() function completes the Map() operation and releases any
  corresponding resources.
  If the operation was an EfiPciOperationBusMasterWrite or
  EfiPciOperationBusMasterWrite64, the data is committed to the target system
  memory.
  Any resources used for the mapping are freed.

  @param[in] This      A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in] Mapping   The mapping value returned from Map().

  @retval EFI_SUCCESS            The range was unmapped.

  @retval EFI_INVALID_PARAMETER  Mapping is not a value that was returned by
                                 Map().

  @retval EFI_DEVICE_ERROR       The data was not committed to the target
                                 system memory.
**/
EFI_STATUS
EFIAPI
RootBridgeIoUnmap (
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN VOID                             *Mapping
  )
{
  MAP_INFO    *MapInfo;

  //
  // See if the Map() operation associated with this Unmap() required a mapping
  // buffer. If a mapping buffer was not required, then this function simply
  // returns EFI_SUCCESS.
  //
  if (Mapping != NULL) {
    //
    // Get the MAP_INFO structure from Mapping
    //
    MapInfo = (MAP_INFO *)Mapping;

    //
    // If this is a write operation from the Bus Master's point of view,
    // then copy the contents of the mapped buffer into the real buffer
    // so the processor can read the contents of the real buffer.
    //
    if (MapInfo->Operation == EfiPciOperationBusMasterWrite ||
        MapInfo->Operation == EfiPciOperationBusMasterWrite64) {
      CopyMem (
        (VOID *)(UINTN)MapInfo->HostAddress,
        (VOID *)(UINTN)MapInfo->MappedHostAddress,
        MapInfo->NumberOfBytes
        );
    }

    //
    // Free the mapped buffer and the MAP_INFO structure.
    //
    gBS->FreePages (MapInfo->MappedHostAddress, MapInfo->NumberOfPages);
    gBS->FreePool (Mapping);
  }
  return EFI_SUCCESS;
}

/**
  Allocates pages that are suitable for an EfiPciOperationBusMasterCommonBuffer
  or EfiPciOperationBusMasterCommonBuffer64 mapping.

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param Type        This parameter is not used and must be ignored.

  @param MemoryType  The type of memory to allocate, EfiBootServicesData or
                     EfiRuntimeServicesData.

  @param Pages       The number of pages to allocate.

  @param HostAddress A pointer to store the base system memory address of the
                     allocated range.

  @param Attributes  The requested bit mask of attributes for the allocated
                     range. Only the attributes
                     EFI_PCI_ATTRIBUTE_MEMORY_WRITE_COMBINE,
                     EFI_PCI_ATTRIBUTE_MEMORY_CACHED, and
                     EFI_PCI_ATTRIBUTE_DUAL_ADDRESS_CYCLE may be used with this
                     function.

  @retval EFI_SUCCESS            The requested memory pages were allocated.

  @retval EFI_INVALID_PARAMETER  MemoryType is invalid.

  @retval EFI_INVALID_PARAMETER  HostAddress is NULL.

  @retval EFI_UNSUPPORTED        Attributes is unsupported. The only legal
                                 attribute bits are MEMORY_WRITE_COMBINE,
                                 MEMORY_CACHED, and DUAL_ADDRESS_CYCLE.

  @retval EFI_OUT_OF_RESOURCES   The memory pages could not be allocated.
**/
EFI_STATUS
EFIAPI
RootBridgeIoAllocateBuffer (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN  EFI_ALLOCATE_TYPE                Type,
  IN  EFI_MEMORY_TYPE                  MemoryType,
  IN  UINTN                            Pages,
  OUT VOID                             **HostAddress,
  IN  UINT64                           Attributes
  )
{
  EFI_STATUS            Status;
  EFI_PHYSICAL_ADDRESS  PhysicalAddress;

  //
  // Validate Attributes
  //
  if ((Attributes & EFI_PCI_ATTRIBUTE_INVALID_FOR_ALLOCATE_BUFFER) != 0) {
    return EFI_UNSUPPORTED;
  }

  //
  // Check for invalid inputs
  //
  if (HostAddress == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // The only valid memory types are EfiBootServicesData and
  // EfiRuntimeServicesData
  //
  if (MemoryType != EfiBootServicesData &&
      MemoryType != EfiRuntimeServicesData) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Limit allocations to memory below 4GB
  //
  PhysicalAddress = (EFI_PHYSICAL_ADDRESS)(0xffffffff);

  Status = gBS->AllocatePages (AllocateMaxAddress, MemoryType, Pages,
                  &PhysicalAddress);
  if (EFI_ERROR (Status)) {
    return Status;
  }

  *HostAddress = (VOID *)(UINTN)PhysicalAddress;

  return EFI_SUCCESS;
}

/**
  Frees memory that was allocated with AllocateBuffer().

  The FreeBuffer() function frees memory that was allocated with
  AllocateBuffer().

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param Pages       The number of pages to free.

  @param HostAddress The base system memory address of the allocated range.

  @retval EFI_SUCCESS            The requested memory pages were freed.

  @retval EFI_INVALID_PARAMETER  The memory range specified by HostAddress and
                                 Pages was not allocated with AllocateBuffer().
**/
EFI_STATUS
EFIAPI
RootBridgeIoFreeBuffer (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN  UINTN                            Pages,
  OUT VOID                             *HostAddress
  )
{
  return gBS->FreePages ((EFI_PHYSICAL_ADDRESS) (UINTN) HostAddress, Pages);
}

/**
  Flushes all PCI posted write transactions from a PCI host bridge to system
  memory.

  The Flush() function flushes any PCI posted write transactions from a PCI
  host bridge to system memory. Posted write transactions are generated by PCI
  bus masters when they perform write transactions to target addresses in
  system memory.
  This function does not flush posted write transactions from any PCI bridges.
  A PCI controller specific action must be taken to guarantee that the posted
  write transactions have been flushed from the PCI controller and from all the
  PCI bridges into the PCI host bridge. This is typically done with a PCI read
  transaction from the PCI controller prior to calling Flush().

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @retval EFI_SUCCESS        The PCI posted write transactions were flushed
                             from the PCI host bridge to system memory.

  @retval EFI_DEVICE_ERROR   The PCI posted write transactions were not flushed
                             from the PCI host bridge due to a hardware error.
**/
EFI_STATUS
EFIAPI
RootBridgeIoFlush (
  IN EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL           *This
  )
{
  //
  // not supported yet
  //
  return EFI_SUCCESS;
}

/**
  Gets the attributes that a PCI root bridge supports setting with
  SetAttributes(), and the attributes that a PCI root bridge is currently
  using.

  The GetAttributes() function returns the mask of attributes that this PCI
  root bridge supports and the mask of attributes that the PCI root bridge is
  currently using.

  @param This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param Supported   A pointer to the mask of attributes that this PCI root
                     bridge supports setting with SetAttributes().

  @param Attributes  A pointer to the mask of attributes that this PCI root
                     bridge is currently using.

  @retval  EFI_SUCCESS           If Supports is not NULL, then the attributes
                                 that the PCI root bridge supports is returned
                                 in Supports. If Attributes is not NULL, then
                                 the attributes that the PCI root bridge is
                                 currently using is returned in Attributes.

  @retval  EFI_INVALID_PARAMETER Both Supports and Attributes are NULL.
**/
EFI_STATUS
EFIAPI
RootBridgeIoGetAttributes (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  OUT UINT64                           *Supported,
  OUT UINT64                           *Attributes
  )
{
  PCI_ROOT_BRIDGE_INSTANCE *PrivateData;

  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS(This);

  if (Attributes == NULL && Supported == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Set the return value for Supported and Attributes
  //
  if (Supported != NULL) {
    *Supported  = PrivateData->Supports;
  }

  if (Attributes != NULL) {
    *Attributes = PrivateData->Attributes;
  }

  return EFI_SUCCESS;
}

/**
  Sets attributes for a resource range on a PCI root bridge.

  The SetAttributes() function sets the attributes specified in Attributes for
  the PCI root bridge on the resource range specified by ResourceBase and
  ResourceLength. Since the granularity of setting these attributes may vary
  from resource type to resource type, and from platform to platform, the
  actual resource range and the one passed in by the caller may differ. As a
  result, this function may set the attributes specified by Attributes on a
  larger resource range than the caller requested. The actual range is returned
  in ResourceBase and ResourceLength. The caller is responsible for verifying
  that the actual range for which the attributes were set is acceptable.

  @param[in]       This            A pointer to the
                                   EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[in]       Attributes      The mask of attributes to set. If the
                                   attribute bit MEMORY_WRITE_COMBINE,
                                   MEMORY_CACHED, or MEMORY_DISABLE is set,
                                   then the resource range is specified by
                                   ResourceBase and ResourceLength. If
                                   MEMORY_WRITE_COMBINE, MEMORY_CACHED, and
                                   MEMORY_DISABLE are not set, then
                                   ResourceBase and ResourceLength are ignored,
                                   and may be NULL.

  @param[in, out]  ResourceBase    A pointer to the base address of the
                                   resource range to be modified by the
                                   attributes specified by Attributes.

  @param[in, out]  ResourceLength  A pointer to the length of the resource
                                   range to be modified by the attributes
                                   specified by Attributes.

  @retval  EFI_SUCCESS     The current configuration of this PCI root bridge
                           was returned in Resources.

  @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge
                           could not be retrieved.

  @retval  EFI_INVALID_PARAMETER Invalid pointer of
                                 EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
**/
EFI_STATUS
EFIAPI
RootBridgeIoSetAttributes (
  IN     EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL  *This,
  IN     UINT64                           Attributes,
  IN OUT UINT64                           *ResourceBase,
  IN OUT UINT64                           *ResourceLength
  )
{
  PCI_ROOT_BRIDGE_INSTANCE            *PrivateData;

  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS(This);

  if (Attributes != 0) {
    if ((Attributes & (~(PrivateData->Supports))) != 0) {
      return EFI_UNSUPPORTED;
    }
  }

  //
  // This is a generic driver for a PC-AT class system.  It does not have any
  // chipset specific knowlegde, so none of the attributes can be set or
  // cleared.  Any attempt to set attribute that are already set will succeed,
  // and any attempt to set an attribute that is not supported will fail.
  //
  if (Attributes & (~PrivateData->Attributes)) {
    return EFI_UNSUPPORTED;
  }

  return EFI_SUCCESS;
}

/**
  Retrieves the current resource settings of this PCI root bridge in the form
  of a set of ACPI 2.0 resource descriptors.

  There are only two resource descriptor types from the ACPI Specification that
  may be used to describe the current resources allocated to a PCI root bridge.
  These are the QWORD Address Space Descriptor (ACPI 2.0 Section 6.4.3.5.1),
  and the End Tag (ACPI 2.0 Section 6.4.2.8). The QWORD Address Space
  Descriptor can describe memory, I/O, and bus number ranges for dynamic or
  fixed resources. The configuration of a PCI root bridge is described with one
  or more QWORD Address Space Descriptors followed by an End Tag.

  @param[in]   This        A pointer to the EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.

  @param[out]  Resources   A pointer to the ACPI 2.0 resource descriptors that
                           describe the current configuration of this PCI root
                           bridge. The storage for the ACPI 2.0 resource
                           descriptors is allocated by this function. The
                           caller must treat the return buffer as read-only
                           data, and the buffer must not be freed by the
                           caller.

  @retval  EFI_SUCCESS     The current configuration of this PCI root bridge
                           was returned in Resources.

  @retval  EFI_UNSUPPORTED The current configuration of this PCI root bridge
                           could not be retrieved.

  @retval  EFI_INVALID_PARAMETER Invalid pointer of
                                 EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL
**/
EFI_STATUS
EFIAPI
RootBridgeIoConfiguration (
  IN  EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL     *This,
  OUT VOID                                **Resources
  )
{
  PCI_ROOT_BRIDGE_INSTANCE              *PrivateData;
  UINTN                                 Index;

  PrivateData = DRIVER_INSTANCE_FROM_PCI_ROOT_BRIDGE_IO_THIS (This);

  for (Index = 0; Index < TypeMax; Index++) {
    if (PrivateData->ResAllocNode[Index].Status == ResAllocated) {
      EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *Desc;

      Desc = &Configuration.SpaceDesp[Index];
      Desc->AddrRangeMin = PrivateData->ResAllocNode[Index].Base;
      Desc->AddrRangeMax = PrivateData->ResAllocNode[Index].Base +
                           PrivateData->ResAllocNode[Index].Length - 1;
      Desc->AddrLen      = PrivateData->ResAllocNode[Index].Length;
    }
  }

  *Resources = &Configuration;
  return EFI_SUCCESS;
}

